Container closures or caps of the reusable type are utilized on a wide variety of products. Typical products include beverages, vitamins, condiments, and the like. Such caps, whether made of plastic or metal, are provided with liners in the form of coated aluminum foil membranes, plastic-coated paper, or other suitable material.
In assembling a liner into a cap or closure for containers, machines generally are employed which feed the inverted caps sequentially to an assemblying station. A strip of lining material or liner also is fed to the assemblying station and is positioned over the inverted caps, where the liners are punched from the strip of lining material and are assembled into the caps. The movement of the caps and lining material to the assembly station, along with the movement of the punch and other assemblying mechanisms generally is controlled by a mechanically interlocked machine involving a large number of cams, gears, and the like. Because of the complex mechanical interaction of parts which are required for the operating sequence, relatively large electric motors also are required to power such machines.
The nature of most cap-lining machines which currently are used also is such that if a change from one cap size or diameter to another is desired, significant modifications must be made to the machine. This requires skilled mechanics and results in considerable "down time" to effect the changeover from one size of caps to another. In many installations, where large numbers of caps of different sizes are manufactured and lined, it is not uncommon to have different machines set-up to handle different sized caps, even though such machines frequently sit idle for long periods of time between the times caps of the particular size for which a machine has been set up are to be lined. In addition, because of the substantial mechanical complexity of most cap lining machines, many opportunities for mechanical failure and the wearing out of parts exist. Consequently, it also has been common practice to provide idle back-up machines for high production facilities to prevent the interruption of production whenever machines require maintenance, which is frequent.
In many cap lining machines of the prior art, if for some reason movement of caps through the punch and insert mechanism should somehow fail, the machines continue to attempt to feed additional caps to the mechanism resulting in a high likelihood of jamming of the machine and a high potential for breaking of machine parts. In the event of such a failure, expensive parts must be replaced, a considerable amount of skilled labor is required and a significant amount of machine "down time" results.
Some cap lining machines simply rely upon the downward movement of the punch through the web of liner material to seat the liner insert into the cap. If this is done, it is necessary for the punch travel to be downward as far as possible into the cap to insure a tight downward pressure on the insert into the cap. This creates another potential for failure since if for some reason the cap feeding mechanism fails to sequentially feed caps, it is possible for the punch and insert mechanism to attempt to insert a second liner insert (or several liner inserts) into a cap at the liner inserting station of the machine. Because of the very close tolerances involved, this results in jamming of the punch and frequently expensive mechanical failures of gears, cams, and levers in the machine.
A cap lining machine which overcomes most of the problems outlined above in the prior art is disclosed in the patent to Kieran U.S. Pat. No. 4,568,406. In particular, sensing switches are employed in the Kieran machine in conjunction with an electric control system to prevent the machine from moving through a subsequent step in its operation unless all previous steps of operation have been properly completed in proper sequence. Operation interruption of the machine of Kieran is accomplished in a jam proof manner. The machine of Kieran U.S. Pat. No. 4,568,406 employs air cylinders in place of mechanical cam-operated mechanisms for the cap advance and punching operation.
In machines of the prior art, including that of Kieran U.S. Pat. No. 4,568,406, however, if the punch itself is not used to seat the cap insert firmly into the cap, it is necessary to provide an additional tamper mechanism, generally located downstream from the punch mechanism in the path of movement of the caps through the machine. For mechanical machines, this requires an additional set of cams synchronized in operation to the operation of the cap feed and punching mechanism. In a machine of the type disclosed in the Kieran U.S. Pat. No. 4,568,406, an additional air cylinder set or the like would be necessary for operating such a tamper mechanism. All of this adds to the complexities of such prior art machines.
It is desirable to provide a cap lining machine which overcomes the disadvantages of the prior art mentioned above and which minimizes the potential for damage in the event caps should become jammed in the machine or fail to move through it for some reason.